The transporting of articles via pneumatic tubes is old and well known. Basically, an object is placed within a container which is then transported by air under either positive or negative pressure from one destination to another. The transport is moved within a closed tube of the same configuration as the carrier extending between the destinations.
One area of commerce which currently uses the pneumatic tube and the transporting of material via the pneumatic tube on a fairly regular basis is the hospital or biomedical research/manufacturing industry. One particular application of this technology is in the area of transporting blood samples, medicines, viral samples or other biological or chemical matter between diverse locations within a hospital or laboratory. In that environment, for example, test tubes are placed within a tube carrier, and are typically secured by foam or clamps within the carrier. The purpose of securing the samples (which are often contained within glass test tubes with rubber stoppers) is to help prevent breakage. When glass breaks or stoppers become dislodged (as can happen when hospital workers fail to properly secure the stopper in the first place), chemical or biological substances can leak into the interior of the carrier.
If the leaking substance is of a large enough quantity, the substance (often a fluid) can leak out of the carrier. In that case, the entire tube transport system could become contaminated with the substance. For example, if a substance (for example, blood, saline or other fluids) were to leak out of a carrier, the substance would interfere with the carriers' efficiency. More specifically, however, fluids escaping from the carrier could make passage of the carrier difficult, resulting in enhanced downtime and increased maintenance expense.
Every day use of the carriers in pneumatic tube systems causes the glide ring seals to become worn, and hence, not maintain the tight, consistent and secure fit within the interior of the carrier tube. As the carriers sometimes reach speeds in excess of 25 feet per second, the rings serve to form an air barrier around the carrier so the carrier does not jam. Also, by minimizing air leakage around the carrier, the rings can minimize the air required to propel the carrier. As the rings become worn with use, the air barrier around the carrier is eliminated and chances of the carrier becoming lodged in the tube increases. Also, it becomes necessary to use much more air pressure to move the carriers at the same rates as with tight, consistent and secure fitting rings.
There exists a need in the field to provide a carrier with accelerator or glide ring seals which are easily replaceable, remain securely attached to the exterior of the carrier, and maintain a tight, consistent and secure fit between the carrier and the interior of the tubes.
There also exists a need in the field to provide a carrier with suitable watertight and airtight properties, such that matter from within the carrier cannot escape to the outside, and matter that has become uncontrollable within the carrier can activate a warning indicator on the exterior of the carrier, so that hospital or other workers who use the carriers will not open carriers that have an activated warning signal, which is indicative of a spill or other abnormal condition within the carrier.
Prior art known to the inventor includes U.S. Pat. No. 4,948,303 to Good, U.S. Pat. No. 4,324,511 to Irish, U.S. Pat. No. 4,219,290 to Golston, U.S. Pat. No. 4,149,685 to Leavelle, and U.S. Pat. No. 3,825,210 to Weaver, which are incorporated herein by reference.
U.S. Pat. No. 4,948,303 to Good discloses a pneumatic tube carrier with a reinforced hinge.
U.S. Pat. No. 4,324,511 to Irish discloses a pneumatic tube carrier with an accelerator ring.
U.S. Pat. No. 4,219,290 to Golston discloses a hinged pneumatic tube carrier with an improved side opening mechanism.
U.S. Pat. No. 4,149,685, granted to Leavelle, Apr. 17, 1979 discloses a pneumatic carrier having identical halves and includes means to adjust the latch mechanism.
U.S. Pat. No. Re. 30,882 granted, Mar. 16, 1982, to Leavelle is directed to an adjustable closure mechanism.
U.S. Pat. No. 3,825,210, granted to Weaver, Jul. 23, 1974 discloses a "clamshell" type pneumatic tube carrier of a bullet configuration wherein the seals which substantially fill the tube are not immediately adjacent the ends but are spaced therefrom.
U.S. Pat. No. 242,459 to Leaycraft Jun. 7, 1881 which discloses a pneumatic tube carrier having asymmetric hinged halves being continuously urged to a closed position by a spring means.
U.S. Pat. No. 359,456 granted to McLaughlin, Mar. 15, 1887 discloses a pneumatic tube carrier including a spindle or the like for wrapping a paper document for security during transportation from one location to another.
U.S. Pat. No. 452,471 granted to Barri, May 19, 1891 discloses a pneumatic tube apparatus wherein an opening in the surface of the container is created by twisting one coaxial section with respect to the other.
U.S. Pat. No. 769,233 granted to Pfluger, Sep. 6, 1904, discloses a cash box for use with a pneumatic tube wherein an opening in the carrier is exposed by relative twisting of the two coaxial elements.
U.S. Pat. No. 811,915 granted to Hager Feb. 6, 1906, discloses a pneumatic tube carrier including a specific stop member to prevent damage to the cylinders when the two coaxial halves are twisted relative to each other.
U.S. Pat. No. 1,169,553 granted to MacMillan, Jan. 25, 1916, discloses a means for securely latching a pneumatic tube carrier such that it does not accidentally open in transport.
U.S. Pat. No. 1,827,000 granted to Duffin Oct. 13, 1931, discloses a container for a roll of paper wherein the exterior container includes a hinge which connects two halves which are identical with the exception of an internal flap on one side for securing the container in a closed condition.
U.S. Pat. No. 2,251,238 granted to Busch, Jul. 29, 1941, discloses a pneumatic carrier wherein the coaxial halves are twisted with respect to each other to expose a window opening and includes a spring actuated locking device.
U.S. Pat. No. 3,401,902 granted to Gouyou-Beauchamps et al, Sep. 17, 1968 discloses a large dimension open top carriage for use in pneumatic conveying of large objects.
U.S. Pat. No. 3,593,948 granted to McClellan, Jul. 20, 1971, discloses a pneumatic carrier wherein identical halves are hinged together along one edge and includes spring means for urging the two halves to a closed cylindrical configuration for transport.
U.S. Pat. No. 3,761,039, granted to Hazell, Sep. 25, 1973 discloses a pneumatic carrier system including means for transferring documents from one individual carrier to another, enabling the use of sharp corners (transfer stations) in the transport tube itself.
U.S. Pat. No. 4,470,730, granted Sep. 11, 1984, to Wutherich discloses a pneumatic tube carrier having a separate pocket means to separate coinage from paper money during transport.
In general, pneumatic tube systems known in the art include a closed continuous passageway having a predetermined inner cross-sectional dimension where the passageway includes a plurality of curves or bends having a predetermined radius. A fluid, such as air, is controllably forced through the passageway in a loop to move a carrier through the passageway. In order for the carrier to move freely through the passageway, the dimensions, and in particular the length, of the carriers being used have been limited by the inner cross-sectional dimension and curvature radius of the passageway. Pneumatic delivery systems are used extensively for the rapid and efficient transportation of a wide variety of articles. These delivery systems are used in a number of business operations, including banks, hospitals, office buildings, industrial plants, and truck terminals as a few examples.
Pneumatic carriers for use in such delivery systems come in a wide range of sizes and shapes to accommodate the physical articles to be transported in the system. As an example, pneumatic carriers are provided for transporting cash, messages, stock transaction slips, letters, blueprints, electronic data processing cards, x-rays, pharmaceutical supplies, and a variety of other small physical objects.
In the past, various mechanisms have been utilized as closure devices for pneumatic tube carriers. For example, many such carriers include an end cap that is hinged with respect to a cylindrical hull on one side of the hull and which has a latch that releasably fastens the end cap to the opposite side of the hull in a closed position. Such carriers employ a variety of fasteners, such as snap fasteners, elastic straps with eyeholes that fit over hooks, or straps that may be secured to bendable posts.
Other types of pneumatic tube carriers are of the side opening variety. One conventional form of such a carrier employs two generally semi-cylindrical sections that are hinged along one longitudinal edge. The hinged sections may be swung toward or away from each other to effectuate opening and closing of the carrier hull. Locking is achieved by virtue of the end caps, which may be twisted to effectuate threaded engagement of the caps onto the carrier hull ends when the hinged hull sections have been closed. That is, the end caps are rotated in such a fashion as to be drawn towards each other onto the ends of the hull, thereby immobilizing the hull sections relative to each other. Rotation of the end caps in the opposite direction releases the hull sections and allows them to be opened.
A preferable configuration utilized by many carrier manufacturers is that of a side opening, wherein the two sides are hinged together, and the two sides are held together when the carrier is closed by use of a hook, or detent or indented type locking lip. Such carriers include latching mechanisms to prevent the door from coming ajar or opening during transit, which could cause the carrier to become lodged in the pneumatic tubes and would also allow the contents of the container to spill out into the tube system. In addition, the instructions for latching such side opening containers or carriers are simple to follow, so that the container can be easily placed within the tube system. Such hinging and locking mechanisms make waterproofing or sealing the carrier a particularly difficult task, as the hinges and locks are embedded within the mold of the carrier, which is generally formed of plastic.
In another type of side opening pneumatic carrier, the access to the carrier is gained by simultaneously pulling and twisting the ends of the carrier to allow the side opening door to be opened. The instructions for such a two-step process are often difficult for many banking customers to follow, and the physical effort and manual dexterity needed to simultaneously pull and twist both ends of the carrier against a spring resistance is often troublesome for many banking customers.
A need has thus arisen for an improved type of pneumatic carrier which overcomes these and other disadvantages associated with the prior art devices. In particular, a need has arisen for a pneumatic tube carrier having easily replaceable glide or travel or accelerator rings which do not interfere with the opening and closing of the carrier. Also, the carrier must be able to maintain its air barrier and tightness within the interior of the tube, despite the fact that it is subjected to a vacuum transport system, and despite the fact that it will be subjected to extreme environmental conditions, such as repeated use, frequent drops, dust and dirt particles, high speed travel, and the like.
Finally, in the past, heat guns were often used to "un-glue" glide rings from their respective tube carriers, as the glide rings had to be well-secured to the carrier. As the carriers proceed through the pneumatic tube carrier systems, they invariably encounter hostile conditions, such as dust, dirt, ruts in the interior tube walls, twists, turns and bends, and so on. Over time, the glide rings wear out, and so, replacement maximizes the performance of the overall system. Thus, replacement should be simplified, while not compromising the strength of the bond between the glide rings and the pneumatic tube carriers. Also, whatever is used to secure the glide ring to the carrier must be of minimal thickness, so the carrier will fit into traditional tubes, without modification as to size.